Absorption and fluorescence spectra of sSRI (a), sSRII
(b, dashed line), pSRII (b, solid line),
and BR (c). Fluorescence spectra are scaled to the same
height as the corresponding absorption spectra. A fluorescence spectrum
of sSRII could not be recorded because of dominating buffer
fluorescence around 560 nm. Buffer fluorescence also is visible in the
short wavelength wing of the sSRI fluorescence band (a).
In the fluorescence spectrum of BR the narrow shoulders at 560 and 620
nm arise from Raman scattering of water.